ZeroAvia Announces Positive Test Results On Power Inverter Tech


Hybrid-powered aircraft developer ZeroAvia announced on Monday (Jan. 22) that it has successfully completed initial testing on its 200kW continuous power inverter design. Describing inverter technology as “highly weight-efficient,” ZeroAvia said its test unit operated at 230kW from 800 volts of direct current (Vdc). “This inverter performance is a large step for change for the industry,” ZeroAvia said.

Inverter technology takes DC power from electric power sources, such as ZeroAvia’s hydrogen fuel cells, converts it to AC power, and controls the flow to electric motors that power an aircraft. Other potential power sources include batteries and other non-hydrogen hybrid systems. The company sees the capability of its inverters to efficiently transform DC power to AC as “an integral part of the zero-emission, hydrogen-electric aviation engines that ZeroAvia is developing.”

ZeroAvia says its core inverter technology has applications across a wide range of engine sizes, starting with its 600kW ZA600 powerplant designed for aircraft with 9 to 19 seats. The 900kW HyperCore electric motor is designed to be stacked in series as the ZA2000, meant to be capable of powering 40- to 80-seat regional airliners.

Val Miftakhov, ZeroAvia founder and CEO, said: “This kind of technological breakthrough will create enormous value for the company and will have massive impact on transitioning the entirety of aviation away from fossil fuels.” 

Mark Phelps
Mark Phelps is a senior editor at AVweb. He is an instrument rated private pilot and former owner of a Grumman American AA1B and a V-tail Bonanza.


  1. 2 out of 4 news articles today are illustrated with computer generated images. The quota for alternatively real stuff must have reached 50%.

  2. Another Rube Goldberg based on the false premise of man-made climate change. To expand human flourishing we should use more fossil fuels, not less. Read Alex Epstein’s “Fossil Future”.

    • You miss the point that we don’t need to flood the atmosphere with CO2 to effect a change, we only need to tip the balance. We only need to cause 0.001% more solar energy to “stick” to the earth than to be re-radiated. And guess what? That’s happening. It’s measurable, and has been measured.
      Tipping the balance is easy, it turns out.
      But why burn fossil fuels (the exhaust from which would kill anything if breathed in any concentration) if we can work out how *not* to? Your gas car could be stranded in a major catastrophe (weather, war, etc.) but your electric could be charged from your roof.

      • We are a LONG way from what you describe. A friend with a Tesla added 9 hours to his drive from the east coast to Chicago due to charging stops. Another friend in FL with a brand-new Chevy Bolt told me just yesterday that when they return to MI for the summer they will need to stop/recharge 9 times! Last week in the severe cold in Chicago there were MANY electric cars temporarily abandoned at various charging stations because they would not accept a charge. Numerous EV owners returning to Ohare airport discovered their EVs were dead and had to be towed home. Meanwhile, all my ICE cars started/ran without fail – and if they had failed to start I knew a simple jump start would have solved the issue. BOTTOM LINE: While I’m not opposed to owning an EV in the future if all those issues are addressed – they are nowhere close to acceptable in most people’s minds (including the thousands of city dwellers who street park and could never recharge at home).

      • You are confusing carbon dioxide with carbon monoxide. CO2 exists naturally. So many believers of the climate change hoax don’t realize that a large percentage of our roads are paved with asphalt, which is made from the biproducts of processing crude oil into fuel. This just one of many examples.

      • The “tip the balance” argument was an early talking point but is now out of favor. This argument was, in essence, that the continued existence of a livable planet was precariously balanced on the head of a pin, intolerant of man-made disturbance. While weaning ourselves off the limited energy resource oil represents is certainly wise, it’s unlikely that our CO2 contribution is going to tip the planet into another Venus.

  3. Couldn’t they eliminate the need for an invertor if they simply used DC motors (instead of AC motors)? I’m guessing there is a reason for using AC motors – but even my high efficiency furnace uses a DC blower motor because it is supposedly more efficient than the AC motor option.

    • I had the same thought. Hoping someone knowledgable might chip in here (instead of the 100% predictable climate hoax BS).

      • Climate has always changed – in fact, we are still warming up from the last ice age and it is still much cooler than when dinosaurs roamed. Neither temp shift in those preiods was due to humans – so why do we think we can stop it now? Pretty arrogant if you ask me. Google it if you don’t beleivve me.

    • The ZA600 motor is a brushless DC motor, which requires sequentially energizing the multiple stator windings…ie;

      ” The ZeroAvia Motor is a 660kW max power, surface permanent magnet based high efficiency
      machine with bidirectional operation…”

      The inverter itself is a well established design configuration. The ZA folks are testing their design with the fuel cell and motor….

  4. From my understanding it has to do with controlling the Frequency or amplitude of the AC current which controls the speed and power of the AC motor. I read an article about 2 or 3 years back but cannot find it presently.

    • The speed of a DC motor is controlled by varying the voltage fed to it. Higher voltage = higher RPM. A variable speed AC motor can be controlled using a constant voltage and varying the frequency of the power. While it may sound more complicated, the frequency method is actually easier because the power generator (AC or DC) operates at a constant voltage. Modern power plants use variable frequency drive systems to run the various pumps and fan motors in their boiler feed systems. My question is how much current can you produce from a hydrogen fuel cell on a watts per pound basis? It’s hard to beat the power to weight ratio of an IC engine. They may not be thermally efficient, but modern engines are pretty powerful for their weight.

        • If you google a VFD (variable frequency drive) you can find a lot on it. I have it on my lathe – slow to a crawl with almost full power. Or, run the motor faster than the rating. Depends on the frequency. The synchronous speed (rpm)of an AC motor is determined by: Frequency x 120, divided by the number of poles in the motor (always even). Change the frequency, you change the speed. Same power (almost!)!

  5. dbier and Tim: your questions are reasonable and logical. Let me take a swing at it for you…

    There is not sufficient room here for the whole course, but let me hit the high points. DC electric motors compare to AC electric motors as follows:
    1) AC motors are more efficient and require less maintenance than DC motors;
    2) DC motors have higher starting torque and are more controllable than AC;
    3) BLDC motors (brushless DC) form an almost perfect compromise, but are more
    expensive and way more sophisticated.

    Turning a propeller in ambient air on the ground usually requires very little starting torque and the propeller pitch can be used to control the propeller speed. With the higher efficiency of the AC motor, coupled with the lower maintenance requirements, aircraft powerplant motors will normally be AC or a hybrid AC/DC type. Another feature is wire guage and the associated weight factor. Wire size is driven by circuit amperage, not voltage. Therefore, a nice 250 volt AC circuit can deliver significant power through smaller wires, but without an inverter, you are stuck with DC.

    Hope this helps!